The present invention relates to a water purifier which delivers a high quality, pure stream of water.
The present invention also relates to a method for controlling a water purifier to optimize the production of pure water by the water purifier.
The need for water purifiers is expanding as water purifiers are needed for the electronic, pharmaceutical and power industries and purified water is needed for the food, beverage and chemical industries. Pure water is also needed for research purposes, pilot facilities and laboratories.
Generally, water purifiers include one or more filtering components and means for directing water through the filtering component(s) so that impurities in the water are removed during passage of the water through the water purifier. Raw, impure water is directed into the water purifier through an inlet and a pure stream of water is obtained from an outlet of the water purifier. The time in which the water remains in each filtering component is often regulated to ensure adequate purification of the water.
In the prior art, there are numerous patents and publications directed to water purifiers. In particular, reference is made to the following U.S. patents:
U.S. Pat. No. 6,086,754 (Watanabe) describes a water purifier including a timer which controls valves to provide for proper sterilization of the water. The valves are associated with components such as a purification unit, a filter and electrodes. For example, the timer controls the energizing period of the electrodes to ensure that water is heated sufficiently to sterilize it.
Also, U.S. Pat. No. 6,080,313 (Kelada) describes a water purifier with several purification and filtration units in a common housing (see FIG. 1). A flowboard serves as a base of the water purifier and has several mounting assemblies designed to receive different cartridges. Each cartridges has a different function, for example, an activated carbon filter cartridge and a disinfection cartridge. The type of cartridge and the order of the cartridges can be varied to provide for any number of different flow arrangements. A circuit may be included to shut the unit down if the concentration of dissolved solids exceeds a preset limit, e.g., when the water purifier is not providing sufficiently pure water.
U.S. Pat. No. 5,741,416 (Tempest, Jr.) describes a water purifier in which the quality of the water at the outflow is determined by measuring its electrical potential and if the electrical potential indicates that the water is not sufficiently pure, then the water is diverted through a feedback loop to pass through for additional purification treatment.
U.S. Pat. No. 5,698,091 (Kuennen et al.) describes a water purifier with a carbon block filter. A flow regulator is provided to ensure that the system operates at an adequate pressure and provides for an adequate exposure time. Specifically, the flow of water through the filter is measured and if it falls below a preset limit, indicative of blockage in the filter, an audio and/or visual indication is provided indicating that the filter needs to be changed.
U.S. Pat. No. 5,547,584 (Capchart) describes a self-contained water purifier (which presumably means that the components are situated in a common housing) including filter components and pumps which control flow of the water through the purifier. A programmable logic controller is associated with the pumps and pressure switches to control operation of the system and shut the system down when an indication of a malfunction is detected.
U.S. Pat. No. 5,126,050 (Irvine et al.) describes a water treatment apparatus including a microprocessor which controls pumps and valves to provide for desired flows through the apparatus.
The water purifiers described in these patents do not include a particular combination of purification and filtering components as in the invention nor do these patents describe a method for controlling a water purifier to optimize the production of pure water as in the invention.
It is an object of the present invention to provide a new and improved water purifier.
It is another object of the present invention to provide a new and improved water purifier which produces a high quality, pure water stream.
It is yet another object of the present invention to provide a new and improved water purifier including several purification/filtration modules which are controlled to achieve overall optimum performance of the water purifier.
It is still another object of the present invention to provide a new and improved water purifier including several purification/filtration modules whose operation is monitored and adjusted if necessary to achieve overall optimum performance of the water purifier.
It is yet another object of the present invention to provide a new and improved method for controlling components in a water purifier with a view toward optimizing and/or maximizing the purification of water, and/or achieving optimum overall performance.
In order to achieve one or more of the objects set forth above, a general embodiment of a water purifier in accordance with the invention has a novel combination of purification and/or filtration components. Further, the water purifier including the purification and/or filtration components is controlled by controlling the individual components in a specific manner.
The water purifier uses membranes, ion exchange resins and electricity to remove ionic, organic and suspended impurities from water, producing a high quality, pure water stream. In the water purifier, raw or supply water is pretreated by directing it first into a sediment pre-filter module, then into a softener module and then into a sediment removal and dechlorination module. The pre-treated water is then supplied in a controlled manner to a reverse osmosis module which separates the water into two streams (a purified water stream and a concentrate stream) by collecting fluids from both sides of pressurized membranes in the reverse osmosis module. The purified water stream is passed to an electrodeionization module which further purifies the water and directs the water to an ultraviolet sterilization module from which pure water is obtained. The concentrate stream is divided into a recycle stream which is passed to the inlet of the reverse osmosis module and a waste concentrate stream which flows to an outlet of the machine.
An important feature of the invention is the presence of a central microprocessor which utilizes a proprietary program to control the modules, valves and pumps to ensure satisfactory water quality and operation of the machine. The microprocessor is coupled to various monitors and sensors associated with the modules and determines the necessary or allowable operation of the valves and pumps. If the valves or pumps deviate from the necessary or allowable operation, the control system is programmed to either automatically correct the deviation or to notify the operator that manual correction is necessary. In this manner, the water purifier will not operate is the conditions for generating pure water are not proper.
One exemplifying embodiment of the water purifier in accordance with the invention comprises a softener module arranged to receive the supply water and remove metallic ions from the water, a de-chlorination module arranged to receive water from the softener module and remove oxidizing and organic compounds from the water, a control valve arranged downstream of the de-chlorination module for regulating flow of water from the de-chlorination module, a reverse osmosis module arranged downstream of the control valve and comprising reverse osmosis membranes which purify the water upon flow of water through the membranes, a pump arranged between the control valve and the reverse osmosis module for pump water at a high pressure through the reverse osmosis module, an electrodeionization module arranged to receive water from the reverse osmosis module and remove ions from the water to provide a stream of pure water, and a control system for controlling operation of the softener module, the de-chlorination module, the control valve, the reverse osmosis module, the pump, the electrodeionization module and the ultraviolet sterilization module to optimize purification of the supply water.
The control valve, pump and modules mentioned above may be arranged in connection with a frame forming a self-contained unit, e.g., arranged in an interior space defined by the frame.
The control system is coupled to various monitors associated with the modules including a flow monitor associated with the softener module for measuring rate of flow of water into the softener module. The control system determines processing capacity of the softener module based on the measured flow rate and initiates regeneration of the softener module, e.g., regeneration of sodium ion resins in a tank, based on analysis of the determined processing capacity of the softener module and a pre-determined capacity of the sodium ion resins.
Another flow monitor is associated with the de-chlorination module for measuring rate of flow of water into the de-chlorination module. An indicator visible from exterior of the water purifier is preferably provided. The control system determines processing capacity of carbon elements of the de-chlorination module and controls the indicator to provide an indication when replacement of the carbon elements is required.
Other monitors include a water quality monitor for measuring ionic concentration in the water, a temperature monitor for measuring temperature of the water, and a pressure monitor for measuring pressure of the water. The control system is preferably designed to activate an indicator or alarm when the measured ionic concentration, temperature or pressure of the water is outside of an operational range and/or user pre-set value.
Another monitor is a water quality monitor for measuring ionic concentration in pure water outlet from the electrodeionization module. The control system calculates electrical voltage and current required by the electrodeionization module and automatically adjusts each to achieve optimum outlet water quality, if such adjustment is necessary.
An optional sediment pre-filter module may be arranged before the softener module and removes particles from the supply water. Pressure sensors measures pressure of ceramic elements of the sediment pre-filter module at an inlet end of the module and at an outlet end of the module. The control system analyzes the pressure readings and determines when the sediment pre-filter module is performing below a threshold satisfaction level indicative of the need to clean the ceramic elements.
Another optional module is an ultraviolet sterilization module arranged after the electrodeionization module and is constructed to eliminate bacteria from the water such that the pure water stream is provided from the ultraviolet sterilization module.
A method for controlling a water purifier including in sequence a softener module, a de-chlorination module, a pump, a reverse osmosis module and an electrodeionization module, entails controlling the softener module, de-chlorination module, reverse osmosis module and the electrodeionization module. Control of the softener module may entail measuring flow rate of water into the softener module, determining whether the processed volume of water by the softener module exceeds the volumetric softening capacity of the softener module, and directing regeneration of the softener module when the processed volume of water exceeds the volumetric softening capacity. Control of the de-chlorination module may entail measuring flow rate of water into the de-chlorination module, determining whether the processed volume of water by the de-chlorination module exceeds the processing capacity of the de-chlorination module, and directing replacement of the de-chlorination module when the processed volume of water exceeds the processing capacity. Control of the reverse osmosis module may entail measuring the flow rate and pressure of an RO permeate stream and an RO concentrate stream generated by the reverse osmosis module, determining whether the flow rates and pressure of the RO permeate stream and RO concentrate stream are within allowable operating margins or non-optimal, and adjusting valves to change at least one of the flow rate and pressure of the RO permeate stream and RO concentrate stream when the flow rates and pressure of the RO permeate stream and RO concentrate stream are determined to be outside of allowable operating margins or non-optimal. Control of the electrodeionization module may entail measuring the flow rate and pressure of an EDI process stream, an EDI electrode stream and an EDI concentrate stream which pass separately through the electrodeionization module, determining whether the flow rates and/or pressure of the EDI process stream, EDI electrode stream and EDI concentrate stream are within allowable operating margins and/or non-optimal, and adjusting valves to change the flow rate and/or pressure of the RO permeate stream and/or RO concentrate stream when the flow rates and/or pressure of the RO permeate stream and/or RO concentrate stream are determined to be outside of allowable operating margins or non-optimal.
The method may also include measuring ionic concentration in the water at a location in the water purifier which is indicative of the quality of the water, determining whether the measured ionic concentration is within allowable margins and optimal, and adjusting the electrodeionization module when the measured ionic concentration is determined to be outside of the allowable margins or non-optimal. Instead of or in addition to adjusting the electrodeionization module, an indicator or warning device may be activated.
The temperature of the water can be measured at a location in the water purifier, a determination is made if the temperature of the water is outside of allowable margins and if so, an indicator or warning device is activated.
Other enhancements of the method include measuring pressure of the water at the softener module, determining if the pressure of the water is outside of allowable margins, and activating an indicator or warning device when the pressure is determined to be outside of allowable margins. Another enhancement is to monitor time of operation of the pump and activate an indicator or warning device when maintenance of the pump is required as determined by elapsed time of operation of the pump.